Security services prepared for worst

Hours before Flight 150 touched down on British soil, a well-rehearsed hostage contingency plan, which involved police negotiators, the SAS, and Government ministers, had been activated.

Awaiting the kidnappers were some of the world's leading experts in anti- terrorism. Within nine hours, all aboard had been released safely and the hijackers arrested. The apparent ease with which this potential crisis was dealt was the result of a well-worked strategy.

Essex police, whose force area covers Stansted, dealt with the bulk of the operation. The hostage-takers had wanted to land at Heathrow, but the flight was diverted to Stansted, 30 miles north-east of London, because it is more isolated and far easier to contain than the two major airports.

As soon as the aircraft landed it was surrounded by armed police officers at an isolated spot on the tarmac. The rest of the airport carried on as normal.

Men from the SAS Counter-Terrorist Team, who are on permanent 24-hour standby at their base near Hereford, were alerted and kept in readiness close to the airport.

But overall control was held by Essex's Chief Constable, John Burrow, who was known as "gold commander".

Up to 500 officers - including an unspecified number of armed units - were involved in the operation, but a three-strong negotiating team had the greatest impact.

Led by Chief Inspector Winston Bernard, the negotiators usually work in pairs with one person taking a break while the others talk and keep notes.

While the talking went on, security experts were drawing together as much information as possible about the layout of the aeroplane, the position of the kidnappers and their type of weapons, in case an armed assault on the aircraft became necessary.

Throughout, ministers, including the Home Secretary and the Foreign Secretary, were kept informed via the Cabinet Office Briefing Room, an emergency committee of senior members of the Government. Any decision to storm the plane would first be discussed by the committee.

But that drastic action was not necessary. An hour and half after the Essex negotiators first made contact by telephone with the hijackers the first hostages were released.